The invention relates to a centrifugal pump for transferring solid particles from a low pressure zone into a high pressure zone, such as a centrifugal pump for supplying coal powder into a high pressure coal gasification reactor.
When supplying coal powder into a high pressure coal gasification reactor, the gas pressure in the reactor has to be overcome, which pressure is usually at least 10 atm. absolute during normal operation. It is known in the art to use for this purpose a centrifugal coal pump. During operation of such pump, the rotor thereof rotates at high rotational speed and coal particles are ejected by centrifugal force from the rotor into a gas-pressurized pump housing and subsequently the particles leave the housing via an outlet that is in communication with the gasification reactor. A disadvantage of these known pumps is the high abrasion of the inner surface of the housing and the coal particles as the particles scour at high speed over the inner surface of the housing. Examples of such centrifugal pumps are contained in U.S. patents such as U.S. Pat. Nos. 3,182,825; 4,049,133; 4,120,410 and 4,360,306.